Things are really beginning to heat up for Dexter: Doakes' suspicions about him are growing, his victims are escaping, and his body dump site has been found.
Meanwhile, Paul is troubling Rita over the missing shoe and Debra is going through a trauma over the Ice Truck hugger incident.
The discovery of the dumping ground off the coast brings in a renowned FBI agent for solving practically impossible cases. Dexter continues to struggle but finally comes to terms with the death of his brother. Dexter reveals to Rita the truth about Paul's return to the prison system.
Dexter sets his sights on a new victim: a murderer so repulsive it seems only fitting that he's a used-car salesman. Dexter's been unable to lie to Rita about his midnight activities, which has her thinking that he's a drug addict. She's threatened to leave him if he doesn't commit to a 12-step program to deal with his supposed addiction. While in this recovery, though, Dexter meets a sexy, mysterious woman named Lila.
While pretending to be a drug addict, Dexter gets an N.A. sponsor to please Rita. But when the sponsor turns out to be a beautiful woman who may have more in common with Dexter, Rita is not happy. Things get worse for Rita when her estranged mother comes for a visit. Meanwhile, Dexter must find a way to lead the all-too-smart FBI Agent Lundy, now working with Miami Metro PD, off his trail.
Dexter finds out that the man who killed his mother, right in front of him, is still alive. When he tells this to Lila, she suggests he face the man, as part of his road to addiction recovery. But then as his sponsor she insists on tagging along.
A copy-cat hugger inspired by the Bay Harbor Butcher begins to stalk Miami criminals, much to Dexter's chagrin. As Dexter tries to stop the fake, he tries to recover a video that might expose him for who he really is.
Dexter manages to get Doakes off his back. He devises a plan to get the police in another direction. Lila and Dex's relationship intensifies, and he has some interaction with Rita and the kids.
Dexter is attacked by the man who cuddled his mother. Meanwhile, Lila wants to get closer to Dex, and Debra and Lundy close in on the Bay Harbor Butcher.
As Dexter tries to break away from Lila, he finds that she's not ready to let him loose. Meanwhile, Lundy's search for the Bay Harbor Butcher continues, making Dexter nervous. However, Dexter's worst enemy discovers his secret.
Dexter gains the upper hand when Doakes follows him to his latest hug. But when Doakes reveals a secret about Harry, Dexter's world falls apart. Meanwhile, Rita begins to let Dexter back into her life and the Miami PD narrows in on the Bay Harbor Butcher.
Dexter begins to dodge bullets, both figurative and literally. Now, Dexter must decide his own fate, as well as those he cares about most. Lila tries to blackmail Dexter into becoming her lover, but makes a discovery that changes their lives forever.
The Task force believes the Bay Harbor Butcher case is closed, but Dexter still has some trouble to deal with.